Coupling L-CL filters and active damping method for interleaved three-phase voltage source inverters

The combination of coupled inductors (CIs) and LCL filters can be a filter configuration to achieve high power density for high current applications. Frequency characteristics (i.e., resonance phenomenon) are changed according to the filter configuration and feedback currents (i.e., inverter-side or grid-side current) for current control loops. Therefore, stability analysis should be performed to guarantee the stable operation. In this paper, through stability analysis of three possible candidates for coupling L-CL filters, a most promising configuration is suggested, and an active damping method is proposed in consideration of lossless and costless. Finally, for the verification, simulation and experiment are performed.